Conventional industrial visual apparatus include a partial pattern matching apparatus and a parallel image processor.
The partial pattern matching apparatus is a visual apparatus which is excellent in recognition accuracy and is widely used for transistor wire bonders and the like. However, the partial pattern matching apparatus has a fixed processing function and hence is not suitable for executing various algorithms at high speed in accordance with objects and purposes.
As a programmable parallel image processor, on the other hand, such an arrangement has been proposed that n.times.n parallel arithmetic circuits are disposed on a local memory able to shift in a multiplicity of directions. Such an apparatus, however, necessarily uses, as an image memory, an independent memory element corresponding to each pixel and, therefore, is uneconomical. In addition, the image processor takes much effort and time to make a decision on summarized data from the many special characteristics of many elements, and the parallel image processor is not good for treating the relationship between many memory elements.
In the image processing, generally, an operation is equally carried out over the whole screen area. For example, the screen area of a television or the like is divided into 256.times.240 meshes, and an operation is carried out on each mesh while a pixel to which attention is being paid is shifted by one mesh (pixel) from the left to the right or from the top to the bottom.
In this operation, it is a frequent practice to make a reference to peripheral pixels, e.g., 3.times.3 or 5.times.5 pixels, with the pixel to which attention is being paid at the center.
Accordingly, it is important to employ an arrangement of partial image memories and a control system therefor suitable for setting and making reference to such partial image data on the grounds of economy of the image processor of this type and for making the same more compact and higher in speed.